SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2f2c84e29bca95d3a2a567ce521b3c47b195f379bd855cb626c5d103e40d279' 
  AND token = 'yChApB1SsstqGzvFPoRxcE/zHUtL1/POMAM05qJswvk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}